Disk drives are information storage devices that use magnetic media to store data and movable read/write elements positioned over the magnetic media to selectively read data from and write data to the magnetic media.
FIGS. 1a-1b illustrate a conventional disk drive device 200. As shown in the figures, a disk 101 is mounted on a spindle motor 102 for spinning the disk 101. A voice-coil motor (VCM) arm 104 carries a head gimbal assembly (HGA) 100. The HGA 100 includes a suspension 111 and a slider 103 mounted on a tail end of the suspension 111. The slider 103 embeds read/write elements (not shown) therein to realize data read/write operation of the slider 103 relative to the disk 101. A voice-coil motor 106 is provided for controlling the motion of the voice-coil motor arm 104 and in turn, controlling the slider 103 to move across the surface of the disk 101 from track to track, thereby realizing data read/write operation of the read/write elements relative to the disk 101. In operation, a lift force is generated by the aerodynamic interaction between the slider 103 incorporating read/write elements and the spinning disk 101. The lift force is opposed by equal and opposite spring force applied by the suspension 111 of HGA 100 such that a predetermined flying height of the slider 103 above the surface of the spinning disk 101 is maintained over a full radial stroke of the voice-coil motor arm 104.
FIG. 1c illustrates the slider 103 shown in FIGS. 1a-1b. The slider 103 is a flexible mounting slider (FMS), which could simplify the assembly process of HGA and the whole disk drive device, and thus has been widely used. As shown in FIG. 1c, the flexible mounting slider 103 includes a slider body 155, a first insulation layer 154 formed on the slider body 155, a lead layer 153 formed on the first insulation layer 154 and a second insulation layer 152 formed on the lead layer 153.
The slider body 155 has an air bearing surface (ABS) 180 and a slider back surface 181 opposite to the ABS 180. A trailing edge 184 is formed on the slider body 155 to connect with the ABS 180 and the slider back surface 181, which is provided with read elements (not shown) and write elements 182 thereon. The trailing edge 184 forms a plurality of slider pads 183 at a position close to the slider back surface 181. In the invention, the slider pads 183 electrically connect with the read/write elements.
The first insulation layer 154 is formed to cover the slider back surface 181 so as to form an electrical insulation layer between the lead layer 153 and the slider body 155. The first insulation layer 154 forms a plurality of openings 170 at positions corresponding to the slider pads 183 of the slider body 155. The lead layer 153 comprises a plurality of leads 171 electrically isolated from each other. One end of each lead 171 forms a first pads 163 corresponding to the slider pad 183, the other end of each lead 171 forms a second pad 156 adapted to electrically connect with the suspension (shown as numeral 111 of FIG. 1b). The lead layer 153 is formed on the first insulation layer 154 and insulated from the slider body 155. The slider pads 183, the openings 170 and the first pads 163 are positioned correspondingly, and the slider pads 183 and the corresponding first pads 163 could pass through the opening 170 and thus electrically connecting with each other.
The second insulation layer 152 is used to form an electrical insulation layer between the lead layer 153 and the suspension (not shown). The second insulation layer 152 forms a plurality of openings 162 at positions thereof corresponding to the second pads 156 of the lead layer 153. The second pads 156 could pass through the opening 162 and thus electrically connect with the corresponding electrical connection pads (not shown) of the suspension via the electrical connection ball.
Because of the existence of the two insulation layers, the read/write elements of the slider 103 could achieve electrical connection with the corresponding parts of the suspension via the slider pads 183 with the lead layer 153. However, in the slider-forming process, because the second insulation layer 152 is provided at the outermost surface of the slider 103, it is very easy for the second insulation layer 152 to rub with the outside surroundings, thus accumulating a large amount of electrostatic charges. Because of the electrostatic induction action, some electrostatic charges are also distributed in the lead layer 153, which makes the lead layer 153 present high potential accordingly. As the second insulation layer 152 has no proper grounding structure, the electrostatic charges are unable to be released before the slider 103 is assembled to the other components. For such reason, during the process of assembling the slider 103 to the other components, it is very easy for the lead layer 153 to contact with the low-potential outside surroundings (such as operators' hands, clamps, etc.), thus generating electrostatic discharge (ESD) which will cause the current flow through the slider read/write elements connected with the lead layer 153, thereby damaging the slider read/write elements.
It is therefore desirable to provide an improved flexible mounting slider to overcome the above disadvantages of the prior art.